Motor fuel



3,023,092 Patented Feb. 27, 1902 3,023,092 MOTOR FUEL Edwin 0. Hook,Chagrin Falls, and David P. Tate, Northfield, Ohio, assignors to TheStandard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing.Filed June 4, 1959, Ser. No. 818,007

1 Claim. (Cl. 44-69) This invention relates to an improved motor fuelcomposition and in particularto a leaded fuel composition for highcompression, spark-ignition engines containing an organic phosphoruscompound.

It is a well-recognized fact today that during the opera- I tion of aninitially clean internal combustion engine on gasoline-type fuelsdeposits form progressively and accumulate on the walls of thecombustion chamber and on the terminals of sparkplugs. These depositscause plug fouling, raise octane number requirement of the engine, andin general reduce appreciably the efiicency of the engine. The depositproblem is particularly aggravated when tetraethyl lead is contained inthe fuel since the deposits now have a metallic nature which manifests amore harmful effect on engine operation than deposits which areessentially of carbonaceous character. In order to obtain a high octanenumber fuel such as is required for modern high compression internalcombustion engines, most fuels require the addition of tetraethyl leadand hence the deposit problem in the combustion zone becomes aggravated.

A number of compounds of phosphorus have been proposed in the past foraddition to gasoline to alleviate these adverse efiects of deposits andparticularly lead deposits which form in the combustion zone of theengine. One of the chief objections to the use of such phosphoruscompounds, however, is that they characteristically lower to some extentthe octane number of the fuel which obviously negates in part theadvantage gained in the first instance when tetraethyl lead is added tothe fuel.

In accordance with the present invention, it has been found that theaddition of diethyl N-(2,4-dimethyl phenyl) amido phosphite to agasoline in amounts to supply the quantity of elemental phosphorusnormally required to alleviate the adverse effects on deposit problemsquite surprisingly increases the octane number of the fuel.

The diethyl N-(2,4-dimethyl phenyl) amido phosphite compound for use inthe fuel of the invention is a known chemical and may be prepared byreacting diethyl chlorophosphite with 2,4-dimethyl aniline in benzene.

The reaction proceeds according to the following equation:

mcmn rouo can).

tonnonr-rmQon. 1101 The amount of diethyl N-(2,4-dimethyl phenyl) amidophosphite to be incorporated in the fuel of the invention depends tosome extent upon the particular fuel employed as well as the amount oftetraethyl lead which is included therein. Amounts of the compound from0.004% to 0.08% by weight based on the total fuel may be usedeffectively.

It is intended that the motor fuel of the invention may also includeother known additives for commercial fuels, such as oxidationinhibitors, gum inhibitors, dyes, solvent oils, and the like.

- When tetraethyl lead is used, the-fuel may also contain a leadscavenging agent such. asa volatile alkyl halide or a mixture ofvolatile alkyl halides such as ethylene dichloride and/or ethylenedibromide. These halides are usually present as 1 theory of ethylenedichloride and b theory of ethylene dibromide (the so-called motor mix)or 1 theory of ethylene dibromide (the so-called aviation mix). Bytheory is meant the stoichiometric amount of the ethylene dihalide forcombination with all of the lead as lead halide.

The base gasoline for the fuel can comprise a mixture of hydrocarbonsboiling in the gasoline range and can be either a straight-run gasolineor a gasoline obtained from a conventional cracking process, or mixturesthereof. The base gasoline may also contain components obtained fromvarious other refinery processes, such as alkylation, isomerization,hydrogenation, polymerization, catalytic reforming, or combinations oftwo or more of such proc' esses.

To demonstrate the beneficial octane effect obtainable when operating anengine with the fuel of the invention, octane ratings were made in anASTM single-cylinder engine in accordance with a test procedure referredto as the Research Method. The operating conditions for this ASTMengine, when running the Research Method determination, is set forth inASTM D908-55. A device is installed in the cylinder head of this ASTMengine so that the pressure impulses from detonation can be detected.These are electronically amplified and their intensity indicated on aknock meter on the engine panel board. The motor fuels to be tested areused as the fuel for the engine. The test fuels are compared in knockintensity with that of various reference fuels which are blends of twostandard compounds-iso-octane (2,2,4- trimethyl pentane) which isassigned an arbitrary number of for the test, and n-heptane which isassigned an arbitrary number of 0. A blend of iso-octane and nheptane isfound which produces the same knock intensity as the fuel under test.The percentage by volume of isooctane and the matching blend isdesignated as the octane number of the gasoline. For example, if a blendof 80% iso-octane and 20% n-heptane is required to duplicate the knockintensity of the test fuel, the fuel would then be given an octanenumber of 80. The base gasoline was the same for all the fuels tested.Fuel 1 contained 0.016% by weight diethyl N-(2,4-dimethy1 phenyl) amidophosphite in accordance with the invention. For comparison, fuels 2 and3 contained phosphorus compounds which have previously been proposed asgasoline additives and which are now in commercial usage. The base fuelhad the following compositions and specifications:

Composition, vol. percent:

Octane number (Research Method) 100.4

Concentration, Change percent Octane in octane Fuel Additive by ratingrating weight, over base hosfuel p iorons Base fuel". None None 100.4 1Diethyl N-(2,4-dimethyl 0. 0021 100. 7 +0. 3

phenyl) amide phosphite. 2 -l Tricresyl phosphate 0.0021 100.1 --0.3 3Dimethyl xylyl phosphate" 0.0021 108. 2 -0. 2

As will be noted from the above table, the addition of diethylN-(2,4-dimethyl phenyl) amido phosphite to the base fuel produced adefinite positive efiect on octane number. By contrast, it is obviousthat known phosphate esters added to the fuel for the same testdemonstrate a definite negative efliect upon octane number.

The invention has been described hereinabove with reference to variousspecific examples and embodiments. 2o

It will be understood that the invention is not limited to such examplesand embodiments but is intended to have References Cited in the file ofthis patent UNITED STATES PATENTS 2,617,794 7 Anderson Nov. 11, 19522,878,255 7 Toy et a1 Mar. 17, 1959 2,892,691 Howell June 30, 19592,897,068 Pellegrini et a1. July 28, 1959 2,911,431 Orlofi et al. Nov.3, 1959 v FOREIGN PATENTS 216,009 Australia July 11, 1958 v 565,182Canada Oct. 28, 1959

